(1) Field of the Invention
The invention relates to a system reliability evaluation method for transmission by a single minimal path in time restriction, and especially relates to a system reliability evaluation method for transmission by a single minimal path of a stochastic-flow network in time restriction.
(2) Description of the Prior Art
With diversification of commodities and information services, various kinds of flow networks which value transmission time has emerged, such as computer system, telecommunication system, logistic system and transportation system, etc. Basically, the flow network is composed by plural nodes and arcs between nodes.
For effectively managing the flow network, the shortest path problem has attracted great attention of researchers in information science, network layout and operation research. The problem is to find a path in the network to send a given amount of data (goods or commodities) from a start node to a terminal node with minimum transmission time. Since then, several related problems are proposed gradually for different applications, such as least cost path problem, largest capacity path problem, shortest delay path problem, etc. Later, the quickest path problem is proposed to seek a path for sending a given amount of data with minimum transmission time without loops.
loops.
Currently, in most researches of the quickest path problem, it is assumed that each arc has two attributes: capacity and lead time, and both are deterministic. However, due to failure, maintenance, occupation, etc., it is more reasonable that the capacity of each arc is stochastic in real-life flow network. Such a network is named a stochastic-flow network.
The stochastic-flow network is much more complex at controlling transmission time. For example, in the computer system, each computer (or switch) represents a node, and each transmission line represents an arc. The transmission line is composed by plural real-life network lines (such as T1 cable or E1 cable), and each network line has two cases of normal and failure. Thus each transmission line has plural states, and capacity of each arc has plural values accordingly.
The capacity of the stochastic-flow network is not deterministic, so the transmission time is not a fixed number and the technology for evaluating deterministic capacity becomes unrealistic. Hence, it is an important issue to conduct the system reliability evaluation method for a stochastic-flow network.